Mobile surface treating apparatus

ABSTRACT

A mobile apparatus for the surface treatment with ferromagnetic particulate material thrown onto the surface at high speed, includes a housing which encloses a device for projecting the material onto the surface. Elements are provided for removal of the particulate material from the surface including air jets for slightly lifting the material, a magnetic drum and a conveyor for attracting the ferromagnetic material and conveying it for subsequent reuse.

1,, :11: rte tats tet 1191 1 1 3,858,359 Leliaert 11111.7, 1975 [5MOBILE SURFACE TREATING 2,181,487 11/1939 Khuen-l ryk 15/345 APPARATUS2,677,461 5/1954 2,684,558 7/1954 [75] Inventor: Raymond M. Leliaert,South Bend, ,004,279 10 1961 1nd. 3,007,191 11/196] [73] Assignee:Wheelabrator-Frye, Inc., Mishawaka, 1nd. 3 75 377 9 973 221 Filed: Jan.10, 1974 R273 [21] Appl. No.: 432,353 Primary Examiner-Donald G. Kelly52 us. c1 51/9, 209/215, 209/219, [571 1 ABSTRACT 209/223 R, 404/94 Amobile apparatus for the surface treatment with fer- [511 1111. Cl.1324c 3/06 romagnetic particulate a e ial thrown onto the sur- [58]Field of Search 51/8 R, 9, 270, 274, 262 R; face at high speed, includesa housing which encloses 15/340, 345, 1; 209/215, 218, 219, 223, 223 adevice for projecting the material onto the surface. A; 404/75, 94Elements are provided for removal of the particulate material from thesurface including air jets for slightly [56] R f r Cit d lifting thematerial, a magnetic drum and a conveyor UNITED STATES PATENTS forattracting the ferromagnetic material and conveying it for subsequentreuse.

12 Claims, 1 Drawing Figure 1,326,561 12/1919 Ady 209/223 A 2,064,34412/1936 GOOCI 15/345 X I 13- i 1 J T I Patented Jan. 7, 1975 1 MOBILESURFACE TREATING APPARATUS This invention relates to a mobile apparatusfor surface treatment with ferromagnetic particulate or abrasivematerial projected at high velocity onto the surface and it relates moreparticularly to means for removal of the particulate material and dustfrom the surface for cleaning the treated surface and recovery of theparticulate material for recycle.

In US. Pat. No. 3,691,689, description is made of a mobile apparatus forcleaning surfaces with a particulate abrasive material, wherein theabrasive particles are thrown centrifugally, at high velocity,downwardly through the bottom open side of a housing enclosing theexposed surface to be cleaned. The particulate material, thrown onto thesurface at high velocity, is prevented for ricocheting into theatmosphere by an apron of resilient material which reaches down to thesurface, but is sufficiently flexible to enable the spent particulatematerial and dust to pass under the apron for subsequent removal fromthe surface by a rotating brush. The brush sweeps the particulatematerial and dust into an elevator which raises the dust and particulatematerial to a dust separator whereby the recovered particulate materialis returned as feed to the throwing wheel.

The brush pickup and recovery means associated therewith represents anextra piece of equipment which materially increases the size of themachine and the cost of operation due to the additional power andequipment required as well as the excessive wear on the brush, requiringfrequent replacement. Further, the rotating brush failed as an effectivepickup of the particulate material and dust, especially when operatingover rough and uneven surfaces.

Other methods of pickup which utilize magnetic means, vacuum means orwhich have employed rebound are described in the following: US. Pat. No.3,034,262 (Paulson); US. Pat. No. 3,380,196 (Mabille), and US. Pat. No.3,448,544 (Cardon). Such means have not been found sufficient to effectclean removal of the spent particulate material and dust. As a result,additional, separate surface cleaning is required to be performed withadditional cost as well as corresponding loss of particulate abrasive.

It is an object of this invention to provide a surface treatingmechanism of the type described which makes use of means for cleaning orotherwise treating relatively flat surfaces with ferromagnetic abrasiveor other ferromagnetic particulate material, thrown at high velocityonto the surface during the surface treating operation, which makes useof magnetic recovery means for removing spent abrasive in which themeans is assisted by an air jet for lifting the spent particulatematerial and dirt from the treated surface which may itself beferromagnetic and in which the elements are combined within a compactassembly for movement over the surface to be treated, and in which useis made of a minimum number of parts which cooperate one with anotherfor operation in a simple and efficient manner, without the need forhighly skilled or experienced labor.

These and other objects and advantages of this invention willhereinafter appear, and for purposes of illustration, but not oflimitation, an embodiment of the invention is shown in the accompanyingdrawing, which is:

A side elevational view, partially in section, showing the essentialelements of the surface treating device embodying the features of thisinvention.

As illustrated in the FIGURE the surface treating apparatus of thisinvention is mounted on a frame 10 having wheels 12 journalled thereon;for movement over substantially flat surfaces 14 to be cleaned orotherwise treated. The movement of the portable unit can be effected byhand, or the unit can be motorized, as a selfpowered unit, for movementover the surface with suitable steering mechanism controlled by anoperator seated on or otherwise working with the unit. Additionally, theunit can be rolled over the surface by a suitable towing mechanism ormachine.

The invention will be described with reference to a cleaning devicewhich makes use of ferromagnetic abrasive particles as a surfacecleaning agent. However, it will be understood that the inventiveconcepts are applicable to portable apparatus for treatment of surfacesother than for cleaning, such as for abrading, peening, polishing, andthe like, and wherein use is made of particulate material such as metalshot or metal grit.

The numeral 20 indicates a storage bin from which the ferromagneticabrasive particles 22 are fed gravitationally downwardly from an outlet24 at the bottom into a funnel 26 which channels the ferromagneticabrasive particles into the central cage of an airless centrifugalblasting wheel 28 which is rotated at high speed, as by means of a motor29.. The abrasive particles are thrown in a pattern with highcentrifugal force from the periphery of the wheel onto the underlyingsurface 14.

Centrifugal blasting wheels of the type described are well known to thetrade and are marketed under the trade name Wheelobrator byWheelabrator-Frye, Inc. of Mishawaka, lnd. The invention is notrestricted to the use of such airless centrifugal blasting wheels forpropelling the abrasive particles at high velocity onto the surface,since other well known means for projecting particles at high speed canbe used, such as an air blast, vapor blast and the like, using suitablenozzles.

In order to confine the dust, dirt and particulate abrasive in a mannerto prevent contamination of the atmosphere and to protect personnel frominjury from abrasive particles traveling at high speed, the blast areais enclosed within a guard housing 30 which terminates a short distanceabove the surface 1-4 and is open at the bottom side so as to expose thesurface for engagement by the particulate abrasive thrown from thewheel. For this purpose, the wheel 28 is mounted in the upper portion ofthe housing 30 in spaced relation above the surface, and adjusted tothrow the abrasive particles in a pattern to engage the surfacerearwardly of the wheel at a slight angle with reference to thedirection of movement of the portable unit.

Since the surfaces to be treated are often uneven or rough, the loweredge of the protective housing 30 terminates a short distance above thesurface. The intervening space between the housing and surface is sealedoff by resilient skirts (omitted for purposes of clarity) which dependfrom the side walls of the housing to the bottom level of the devicewhereby the resilient skirts engage the surface in a manner toaccommodate any unevenness.

After the magnetic abrasive material has been thrown onto the surface14, it is recovered for reuse by means now to be described. Locatedrearwardly of the abrasive discharge housing 30 is a drum 32 formed ofnon-magnetic metal. The drum rotates about a horizontal axis 34.Disposed along a portion of the internal circumference of the drum in afixed position are a series of permanent magnets 36. The magnets may beplaced about the circumference in a variety of configurations; however,the semicircular arrangement illustrated in the figure is preferred.Entrained about the drum 32 and an idler pulley 38 is a non-magneticflexible belt 40. During operation of the apparatus the drum and pulleyare rotated by a motor (not shown) to cause the belt entrained thereonto rotate in the direction indicated by the arrows. The abrasivematerial is attracted to the drum onto the nonmagnetic belt 40. The beltcarries the abrasive material out of the magnetic field of the drum inpockets formed between a plurality of ribs 42 to a dumping point on theidler pulley 38.

An alternate drum construction wherein the drum itself is magnetic ispossible. In such case the internal fixed magnets 36 are unnecessary.This construction, however, has the disadvantage of applying magneticforce to the abrasive material around the entire circumference of thedrum and therefore tends to interfere with the action of the belt 40 incarrying the abrasive material attracted by the drum away from the drumsforce field. Also, a large magnetic drum is more expensive and moredifficult to fabricate.

Positioned rearwardly of the drum are a plurality of air jets 44 mountedon a manifold 46 which is supplied by an air pump 48. The air jets aredirected in a manner so as to slightly lift the abrasive material offthe surface 14 in the vicinity of the drum 32. Additional jets may beutilized to blow stray abrasive material into the path of the drum.

As will be apparent from the foregoing, as the rotating drum approachesthe magnetic abrasive material the jets of air lift the materialslightly off the surface 14. This allows the abrasive to be attracted tothe drum onto the nonmagnetic belt 40 due to the magnets 36 positionedinside the drum. Use of air jets to lift the abrasive material allowsthe invention to be used for abrasive recovery even from a surface whichis itself magnetic.'By lifting the abrasives off the surface, magneticinterference from a ferromagnetic surface is avoided. The levitatedmagnetic abrasive material is attracted to the drum and as the drumrotates, the material is seated in the pockets formed between the ribs42 on the belt 40. The belt conveys the abrasive material from therotating drum and out of its magnetic field to the idler pulley where itdischarges the material into the boot 49 of a belt and bucket elevator50.

The belt and bucket elevator 50 is indicated schematically only as suchelevators are well known to those Skilled in the art. The abrasives arecarriedupwardly on the elevator and deposited onto a rotary-screen 52for removal of trash and large particles which are commin gled with theabrasive material. A receptacle 54 receives the trash while the abrasivematerial passes downwardly into an air wash separator 56 for removal offine abrasives which are no longer useful, and of sand, dust and otherparticulate material which may detrimentally affect the component wearof the system.

The magnetic drum will pick up ferromagnetic abrasive and waste materialcommingled therewith leaving little or no residue along the surfacedirectly beneath the drum. Abrasive material which has spread outsidethe path of the drum but is still within the flexible seals of themachine may be blown into the path of the drum by positioning additionalair jets, as mentioned, in a suitable manner depending upon theparticular application for which the machine is employed.

The apparatus described finds beneficial use for cleaning or treatmentof surfaces, such as ships decks, metal tank roofs, metal tank walls,concrete or asphalt highways and sidewalks, parking lots, driveways,aircraft runways, landing strips, building floors, and roadway stripesor other markings applied to highways.

It will be understood that changes may be made in the details ofconstruction, arrangement and operation, without departing from thespirit of the invention, especially as defined in the following claims.

I claim:

1. In a mobile apparatus for surface treatment with ferromagneticparticulate material, an enclosure having an open bottom side throughwhich the surface to be treated is exposed, means mounting the enclosurefor movement over the surface, projecting means within the enclosure fordirecting particulate material through the open bottom side onto thesurface to be treated, means for removal of spent ferromagneticparticulate material from the surface, and means for recovering reusableparticulate material; the improvement wherein the means for removal ofspent particulate material from the surface comprises:

air jets positioned to direct an air stream at the surface to elevatethe particulate material slightly above said surface;

means for magnetically attracting the elevated particulate material; and

belt means for transferring the attracted particulate material to thebeams for recovering.

2. The apparatus of claim 1 wherein said means for magneticallyattracting includes a rotating drum of non-magnetic metal and aplurality of permanent magnets placed at fixed locations along the innercircumference of said drum whereby said magnets attract said particulatematter to the outer circumference of said drum.

3. The apparatus of claim 2 wherein said magnets are placed at fixedlocations along only a portion of the inner circumference of said drum.

4. The apparatus of claim 2 wherein said belt means is entrained aboutsaid drum and the particulate material is attracted onto the belt means.

5. The apparatus according to claim I wherein the belt means is formedof flexible nonmagnetic material having a plurality of ribs on its outerperiphery.

6. The apparatus according to claim 1 wherein the air jets are mountedon a manifold and supplied by an air pump.

7. The apparatus according to claim 1 wherein the means for recoveringincludes:

a bucket and belt elevator for carrying the particulate material,

a rotating screen receiving the particulate material from said elevatorfor separating coarse waste materials from reusable abrasives; and

an air wash separator receiving the particulate material from saidscreen for separating reusable abrasive from sand, grit and spentabrasive.

8. A surface treating apparatus as claimed in claim 1 further includinga resilient side apron extending from the bottom side edges of theenclosure into resilient engagement with the surface.

11. The apparatus of claim 1 where said means for magneticallyattracting includes a rotating magnetic drum whereby said drum attractssaid particulate material to its outer circumference.

12. The apparatus of claim 111 wherein said belt means is entrainedabout said drum and the particular material is attracted onto the beltmeans.

1. In a mobile apparatus for surface treatment with ferromagneticparticulate material, an enclosure having an open bottom side throughwhich the surface to be treated is exposed, means mounting the enclosurefor movement over the surface, projecting means within the enclosure fordirecting particulate material through the open bottom side onto thesurface to be treated, means for removal of spent ferromagneticparticulate material from the surface, and means for recovering reusableparticulate material; the improvement wherein the means for removal ofspent particulate material from the surface comprises: air jetspositioned to direct an air stream at the surface to elevate theparticulate material slightly above said surface; means for magneticallyattracting the elevated particulate material; and belt means fortransferring the attracted particulate material to the beams forrecovering.
 2. The apparatus of claim 1 wherein said means formagnetically attracting includes a rotating drum of non-magnetic metaland a plurality of permanent magnets placed at fixed locations along theinner circumference of said drum whereby said magnets attract saidparticulate matter to the outer circumference of said drum.
 3. Theapparatus of claim 2 wherein said magnets are placed at fixed locationsalong only a portion of the inner circumference of said drum.
 4. Theapparatus of claim 2 wherein said belt means is entrained about saiddrum and the particulate material is attracted onto the belt means. 5.The apparatus according to claim 1 wherein the belt means is formed offlexible nonmagnetic material having a plurality of ribs on its outerperiphery.
 6. The apparatus according to claim 1 wherein the air jetsare mounted on a manifold and supplied by an air pump.
 7. The apparatusaccording to claim 1 wherein the means for recovering includes: a bucketand belt elevator for carrying the particulate material, a rotatingscreen receiving the particulate material from said elevator forseparating coarse waste materials from reusable abrasives; and an airwash separator receiving the particulate material from said screen forseparating reusable abrasive from sand, grit and spent abrasive.
 8. Asurface treating apparatus as claimed in claim 1 further including aresilient side apron extending from the bottom side edges of theenclosure into resilient engagement with the surface.
 9. The surfacetreating apparatus of claim 1 in which the particulate material isprojected onto the surface within the enclosure in a downwardly andrearwardly direction.
 10. The surface treating apparatus of claim 1 inwhich the projecting means comprises a bladed wheel mounted forrotational movement at high speed for projecting particulate materialcentrifugally onto the surface.
 11. The apparatus of claim 1 where saidmeans for magnetically attracting includes a rotating magnetic drumwhereby said drum attracts said particulate material to its outercircumference.
 12. The apparatus of claim 11 wherein said belt means isentrained about said drum and the particular material is attracted ontothe belt means.